MODE-2216 Fixed the potential corruption of the workspace cache during concurrent modifying of the same nodes. With the previous code, multiple session writers of the same nodes could cause a "transient" (local) change to be loaded in the workspace cache during the persistChanges call. This because changed nodes are cleared asynchronously from the workspace cache which is not subject to ISPN locking.
The solution was to use a "transient" workspace cache during the persistChanges call, which always contains the latest ISPN stored data after locks has been successfully obtained.
Merge pull request #1139 from hchiorean/MODE-2216-3.x

Mode 2216 3.x - Fixed the potential corruption of the workspace cache during concurrent modifying of the same nodes.